Don,t know a lot about heraldry,there is a RootsChatter who really is very well informed, with a bit of luck they will see your post and be able to help.
My twopennorth for what it is worth , the stag at the very top could be the symbol of The White Hart,that was Richard The Second,Richard of Bordeaux
the son of The Black Prince.
There is a crown under the hart which may denote royalty or royal connections.
There is a special name for. The three flower like things on the diagonal bar.
I used to think that the left sloping bar was an indication that there was illegitimacy somewhere- the bar sinister but the expert I have mentioned said that was not the case.
Scroll back through,it must be several months ago but the person I mentioned has obviously done a great deal of work and iis really very
knowledgeable.
Best of luck.Viktoria.